A D.C. man pleaded guilty to second-degree murder and robbery Friday in the 2016 killing of a Fairfax County’s teacher’s aide, who investigators say came upon two men breaking into cars and was shot.

Charles Edward Benson was one of two men charged in the killing of Tarreece Sampson, 24, who was killed in the parking lot of his apartment building in the early hours of May 20, 2016, as a friend listened on the phone. Benson faces up to life in prison when he is sentenced on Dec. 20.

Sampson, who was a popular aide at Fort Hunt Elementary School and a graduate student at George Mason University, had returned home from a night out and was on the phone with his friend Patrick Cuffey when the violence unfolded.

Cuffey testified at a January preliminary hearing that he heard Sampson say to someone, “Hey, are you good?” Cuffey then heard a single shot. The gunfire was followed by a gurgling sound, but not another word from Sampson.

Cuffey eventually called 911, but Sampson was pronounced dead on the scene at the Cityside apartments. He was robbed of personal items.

Blake Woloson, an attorney for Benson, said his client was regretful about what happened.

“He feels bad about what happened to the young man,” Woloson said. “It wasn’t his intention that anyone get shot. It’s a tragedy for everyone.”

Tre’Sur Hawkins, of the District, is slated to stand trial on first-degree murder in the case in November.